This invention relates to a device for centering and internal clamping of tubular parts such as metal conduits, placed end-to-end so as to be welded to form metal pipelines.
In the welding of these conduits, it is essential for the axes of said conduits to be properly aligned and for the aligned conduits to be held during the welding. Indeed, if there is poor alignment of the axes, the assembly seal between conduits is then irregular, which from the perspective of quality of the welding performed, can lead to defects. A centering and clamping device therefore makes it possible to align the conduits in preparation for welding and to maintain this alignment during welding. Such devices are described in particular in EP 1123774 and EP 0767719.
A device of this type is conventionally made of an elongate cylinder that has clamping means, such as front and rear clamping shoes, placed on the entire periphery and arranged so as to project radially from said cylinder so as to come into contact with the walls of the conduits to be clamped, which device is capable of also comprising drive means enabling it to move inside the conduits once the welding has been completed.
Such devices require the use of a handle or a rope for controlling, moving and positioning the device at the ends of the conduits to be welded. Such a handle must in particular be caught on leaving the conduit in formation so as to be inserted into the new conduit to be welded.
Thus, document U.S. Pat. No. 6,915,943 proposes an internal centering and clamping device that is controlled by a diesel engine that actuates a hydraulic pump so as to cause the operation of the hydraulic equipment of the device, such as clamping shoes, cylinders enabling deployment of the wheels, and the brakes. A control unit is provided on such a device and comprises a radio receiver that can receive control signals resulting in electrical control commands so as to actuate the hydraulic and electrical components of the device. A remote control unit is then provided, which enables an operator to transmit, by radio, to the control panel of the device, the various orders relating to the operation of the device, in particular forward and backward movement orders for its proper positioning. Thus, with these radio transceivers, the device no longer needs a handle or a rope to move, position or cause the operation of the device. In addition, the time needed to position and actuate said device is advantageously reduced.
Such a device is indeed advantageous, but it has a disadvantage in that it uses hydraulic control equipment and a thermal engine. Indeed, with hydraulic control systems, if the medium used is leading to oil leakages, it may be necessary to redo the welding.
In devices in which the equipment is pneumatically controlled, the handle, while having a handling disadvantage, has a notable advantage in that it enables a simple connection between the tank of the device and the compressor of the welding station.
To overcome the aforementioned disadvantages, this invention proposes a device for centering and clamping tubular parts such as conduits intended to form pipelines, of the type constituted by an elongate cylinder that contains in particular clamping means, so that at least two series of clamping shoes, placed on the entire periphery and arranged to project radially from said cylinder so as to come into contact with the walls of the conduits to be clamped, as well as means for driving each series of clamping shoes between a position of projection from the cylinder and a position in which they are hidden in the cylinder, wherein said drive means can be actuated by pneumatic control means. The cylinder comprises, in the front portion, means for connection to complementary connection means provided at the end of a flexible conduit connected to an external compressor, for supplying compressed air to a tank provided in said device, which means are of the rapid safety connection type.
Thus, advantageously, a pneumatically controlled centering and clamping device is obtained without requiring the connection of said device to a compressor of the welding station by means of a rigid bar, with the tank enabling the pneumatic control while the connection means of the rapid safety connection type and the flexible conduit enable simple and reliable filling of said tank when necessary.
The connection means provided on the device are preferably constituted in part by the male fitting and the female fitting of the rapid safety connection, and the other being provided at the end of a flexible pipe constituting a flexible supply line from the compressor unit. This flexible supply line, constituted by the flexible pipe conduit, makes it possible to eliminate many constraints associated in particular with the rigidity of the bar previously used.
Also advantageously, the centering and clamping device according to the invention no longer requires the presence of a rigid handle, as was the case previously. Consequently, it is possible to provide means for radio control of said device. Thus, the device according to the invention can advantageously comprise a control unit comprising at least one radio receiver for receiving radio control signals transmitted from a remote control unit.
The device according to the invention is very advantageously simpler to use because it can be controlled remotely without any risk for the operators, while ensuring optimal pneumatic operation by the connection means of the rapid safety connection provided at the end of a flexible pipe so as to enable the tank of the device to be refilled.